<?php
/**
 * Text Helper
 *
 * Text manipulations: Highlight, excerpt, truncate, strip of links, convert email addresses to mailto: links...
 *
 * PHP 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.View.Helper
 * @since         CakePHP(tm) v 0.10.0.1076
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

App::uses('AppHelper', 'View/Helper');
App::uses('Hash', 'Utility');

/**
 * Text helper library.
 *
 * Text manipulations: Highlight, excerpt, truncate, strip of links, convert email addresses to mailto: links...
 *
 * @package       Cake.View.Helper
 * @property      HtmlHelper $Html
 * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html
 * @see String
 */
class TextHelper extends AppHelper
{

    /**
     * helpers
     *
     * @var array
     */
    public $helpers = array('Html');

    /**
     * An array of md5sums and their contents.
     * Used when inserting links into text.
     *
     * @var array
     */
    protected $_placeholders = array();

    /**
     * String utility instance
     *
     * @var stdClass
     */
    protected $_engine;

    /**
     * Constructor
     *
     * ### Settings:
     *
     * - `engine` Class name to use to replace String functionality.
     *            The class needs to be placed in the `Utility` directory.
     *
     * @param View $View the view object the helper is attached to.
     * @param array $settings Settings array Settings array
     * @throws CakeException when the engine class could not be found.
     */
    public function __construct(View $View, $settings = array())
    {
        $settings = Hash::merge(array('engine' => 'String'), $settings);
        parent::__construct($View, $settings);
        list($plugin, $engineClass) = pluginSplit($settings['engine'], true);
        App::uses($engineClass, $plugin . 'Utility');
        if (class_exists($engineClass)) {
            $this->_engine = new $engineClass($settings);
        } else {
            throw new CakeException(__d('cake_dev', '%s could not be found', $engineClass));
        }
    }

    /**
     * Call methods from String utility class
     */
    public function __call($method, $params)
    {
        return call_user_func_array(array($this->_engine, $method), $params);
    }

    /**
     * Adds links (<a href=....) to a given text, by finding text that begins with
     * strings like http:// and ftp://.
     *
     * ### Options
     *
     * - `escape` Control HTML escaping of input. Defaults to true.
     *
     * @param string $text Text
     * @param array $options Array of HTML options, and options listed above.
     * @return string The text with links
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoLinkUrls
     */
    public function autoLinkUrls($text, $options = array())
    {
        $this->_placeholders = array();
        $options += array('escape' => true);

        $pattern = '#(?<!href="|src="|">)((?:https?|ftp|nntp)://[a-z0-9.\-:]+(?:/[^\s]*)?)#i';
        $text = preg_replace_callback(
            $pattern,
            array(&$this, '_insertPlaceHolder'),
            $text
        );
        $text = preg_replace_callback(
            '#(?<!href="|">)(?<!\b[[:punct:]])(?<!http://|https://|ftp://|nntp://)www.[^\n\%\ <]+[^<\n\%\,\.\ <](?<!\))#i',
            array(&$this, '_insertPlaceHolder'),
            $text
        );
        if ($options['escape']) {
            $text = h($text);
        }
        return $this->_linkUrls($text, $options);
    }

    /**
     * Saves the placeholder for a string, for later use. This gets around double
     * escaping content in URL's.
     *
     * @param array $matches An array of regexp matches.
     * @return string Replaced values.
     */
    protected function _insertPlaceHolder($matches)
    {
        $key = md5($matches[0]);
        $this->_placeholders[$key] = $matches[0];
        return $key;
    }

    /**
     * Replace placeholders with links.
     *
     * @param string $text The text to operate on.
     * @param array $htmlOptions The options for the generated links.
     * @return string The text with links inserted.
     */
    protected function _linkUrls($text, $htmlOptions)
    {
        $replace = array();
        foreach ($this->_placeholders as $hash => $url) {
            $link = $url;
            if (!preg_match('#^[a-z]+\://#', $url)) {
                $url = 'http://' . $url;
            }
            $replace[$hash] = $this->Html->link($link, $url, $htmlOptions);
        }
        return strtr($text, $replace);
    }

    /**
     * Links email addresses
     *
     * @param string $text The text to operate on
     * @param array $options An array of options to use for the HTML.
     * @return string
     * @see TextHelper::autoLinkEmails()
     */
    protected function _linkEmails($text, $options)
    {
        $replace = array();
        foreach ($this->_placeholders as $hash => $url) {
            $replace[$hash] = $this->Html->link($url, 'mailto:' . $url, $options);
        }
        return strtr($text, $replace);
    }

    /**
     * Adds email links (<a href="mailto:....) to a given text.
     *
     * ### Options
     *
     * - `escape` Control HTML escaping of input. Defaults to true.
     *
     * @param string $text Text
     * @param array $options Array of HTML options, and options listed above.
     * @return string The text with links
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoLinkEmails
     */
    public function autoLinkEmails($text, $options = array())
    {
        $options += array('escape' => true);
        $this->_placeholders = array();

        $atom = '[a-z0-9!#$%&\'*+\/=?^_`{|}~-]';
        $text = preg_replace_callback(
            '/(' . $atom . '+(?:\.' . $atom . '+)*@[a-z0-9-]+(?:\.[a-z0-9-]+)+)/i',
            array(&$this, '_insertPlaceholder'),
            $text
        );
        if ($options['escape']) {
            $text = h($text);
        }
        return $this->_linkEmails($text, $options);
    }

    /**
     * Convert all links and email addresses to HTML links.
     *
     * ### Options
     *
     * - `escape` Control HTML escaping of input. Defaults to true.
     *
     * @param string $text Text
     * @param array $options Array of HTML options, and options listed above.
     * @return string The text with links
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::autoLink
     */
    public function autoLink($text, $options = array())
    {
        $text = $this->autoLinkUrls($text, $options);
        return $this->autoLinkEmails($text, array_merge($options, array('escape' => false)));
    }

    /**
     * @see String::highlight()
     *
     * @param string $text Text to search the phrase in
     * @param string $phrase The phrase that will be searched
     * @param array $options An array of html attributes and options.
     * @return string The highlighted text
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::highlight
     */
    public function highlight($text, $phrase, $options = array())
    {
        return $this->_engine->highlight($text, $phrase, $options);
    }

    /**
     * @see String::stripLinks()
     *
     * @param string $text Text
     * @return string The text without links
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::stripLinks
     */
    public function stripLinks($text)
    {
        return $this->_engine->stripLinks($text);
    }

    /**
     * @see String::truncate()
     *
     * @param string $text String to truncate.
     * @param integer $length Length of returned string, including ellipsis.
     * @param array $options An array of html attributes and options.
     * @return string Trimmed string.
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::truncate
     */
    public function truncate($text, $length = 100, $options = array())
    {
        return $this->_engine->truncate($text, $length, $options);
    }

    /**
     * @see String::excerpt()
     *
     * @param string $text String to search the phrase in
     * @param string $phrase Phrase that will be searched for
     * @param integer $radius The amount of characters that will be returned on each side of the founded phrase
     * @param string $ending Ending that will be appended
     * @return string Modified string
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::excerpt
     */
    public function excerpt($text, $phrase, $radius = 100, $ending = '...')
    {
        return $this->_engine->excerpt($text, $phrase, $radius, $ending);
    }

    /**
     * @see String::toList()
     *
     * @param array $list The list to be joined
     * @param string $and The word used to join the last and second last items together with. Defaults to 'and'
     * @param string $separator The separator used to join all the other items together. Defaults to ', '
     * @return string The glued together string.
     * @link http://book.cakephp.org/2.0/en/core-libraries/helpers/text.html#TextHelper::toList
     */
    public function toList($list, $and = 'and', $separator = ', ')
    {
        return $this->_engine->toList($list, $and, $separator);
    }

}
